A vehicle horn is a sound-making device used to warn others of the approach of the vehicle or of its presence. Automobiles, trucks, ships, and trains are all required by law in some countries to have horns. Bicycles are also legally required to have an audible warning device in many jurisdictions, but not universally, and not always a horn.
Although horns have been standard in vehicles for many years, vehicle telemetry systems are relatively new. In general, vehicle telemetry systems facilitate data or information transfer between a vehicle and a remotely-located user. The user typically receives data from and/or sends data to a vehicle through a personal computer, personal digital assistant (PDA), or other electronic device. Various vehicle telemetry systems can be used to communicate various types of information, such as vehicle security information, vehicle position/location, driver trip information, jurisdiction boundary crossing information, fuel consumption information, driver-messaging, and information relating to remote diagnostics, such as monitoring the wear and tear of the vehicle and its various components, among others.